Process of manufacturing lubricating oils



Patented Dec. 15, 1925.

UNITED STATES PATENT or-rice.

nrcnnnn HANNA, or PIEDMONT, AND ORVILLE ELLswoE'rH, CUSHMAN AND THEODORE WILLIAM noELL, F BERKELEY, CALIFORNIA, ASSIGNORS '10 STANID- ARD' OIL COMPANY, OF SAN FRANCIS CO, CALIFORNIA, A CORPORATION OF. CALI- EnocEss-oE m'anurao'ronme LUBRICATING onls.

'FORNTA.

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To all whom it may concern f i eating oils has proceeded under the common Be it known that we, RICHARDV. HANNA, QRVILLE ELLSWORTH CUSHMAN, and Time- DORE WVILLIAM D'oELL, citizensof the United .States, and residing-in the cities'of Piedmont and Berkeley, respectively,'county of Alameda, and State of California, have'm- "ented anew and useful Process of Manufacturing Lubricating Oils, of which the" following is a specification. a

This invention relates to the art of manufacturing lubricating oils, from petroleum oils. i I

In the copending application of 'Richard V. Hanna, John B. Terry, Ralph A. Holloran and Edwin D. Gray, Serial No. 591,638, filed September 30, 1922, there is set forth a process of manufacturing improved and high grade lubricating oils wherein a petroleum oil is subjected to requisite conditions of pressure and temperature'in order to decompose a part of such oil and to polymerize-and stabilize the residuum. The residuumfrom such polymerizing and stabilizing action is then utilized to produce a highly stabilized. lubricating oil, all as more fully set forth i n'the application mentioned above.

As was also pointed out in this copending application the prior production of lubritheory of the art that high temperature and prolonged heating in the treatment or distillation of petroleum hada detrimental and undesirable effect on the quality of the lubricating oil which would be produced. It has been generally considered that under heat and pressurelubricating stocks werecracked and rendered more unstable and that generally the oil was renderedinferior for lubricating pur oses. In accordance with this theory the distillation of petroleum roduction of lubricating oil has for the been con ucted under the minimum heating and lowest temperature which economical considerations would ermit.

7 It was pointed out.1n the copending application heretofore referred to that while high temperature, prolonged heating, or destructive distillation decomposes a part of the lubricating stock, the body of. the residual oil has undergone avery marked g and th t there exist fractions. in the cation referred to above an reflected light will possess a erally a stock not so distilled Application filed April 28, 1924, Serial No. 709,681.

residual oil fully as high or higher in viscosity than the original oil, and that these fractions have been stabilized and greatly improved in a number of respects, It appears that under the requisiteheating and- .pressure the unstable fractions of the petroleum oil are either cracked and distilled off, thus being removed from the residuum, or that they are polymerized and retained in the oil in a much more stable form than they existed previously to the heating or cracking process. 0

It was the practice as set forth in the above mentioned copending application, 'to distill theresiduum so desired in order to separate the oil content thereof from thetar and carbonaceous matter which results from a decomposition of certain lngredients or unstable fractions of the petroleum oil which is so distilled for a lubricating oil stock. The separate fractions having the viscositydesired for the production of lubri cating oil were then separated from the relatively less viscous fractions by a reducing operation. The reduced oil was then refined with an acid if desired and the acidt-reated oil filtered or otherwiseclarified.

The present invention is an im rovement of rocess described in the co en ing applidiscloses certain improvements in the method as therein set forth.

It sometimes becomes desirable to produce a lubricating oil which will possessa rich green fluorescence, that is, when viewed by en color. It is also known to'those familianwith the art that oils without this green fluorescence are generally characterized by a bluish color when viewed by reflectedlight.

.Various reasons'have been given for the presence of this green fluorescence in certain oils and a blue colorin others. It is gentrue that anoil produced from an overhead stock, that is, a stock that has been subjected to distillation for its separation from a, base, in which-distillation certain desired fractions arethrown over, will have a blue fluorescence wherea an oil made from u stock from a bottom will have a green fluorescence. Thus in the manufacture of lub'ricating oils front eastern or'paraflinebase oils a rich green fluorescence will result if the residuum remaining, after the removal of the gasoline, kerosene and other light fractions, is not subjected to a distillation whereincrack ng temperatures are reached for the conversion 1 of the wax into the crystalline 'state, so that the wax may be removed by a wax-pressing process; in other words, if the wax is removed from the residuum by a cold settling or by a centrifuging method-or other method whereby the wax may be removed in the amorphous state without the production of an overhead stock by a distillation process, a rich green fluorescence will result. Whcn such distillation is resorted to for the conversion of the wax into the crystalline state, a blue fluorescence results.

It will thus be seen that especially in the production of lubricating oils from asphaltic or mixed base crude wherein it is necessary to conduct a distilling operation to separate the lubricating oil as an overhead stock from the asphaltic residuum, the resulting oil as heretofore manufactured will be characterized by a bluish fluorescence.

'So far as we are able to ascertain there has not heretofore been known a satisfactory method for the production of a lubrieating oil, from an asphaltic or mixed base crude,- having a rich green fluorescence; nor from an eastern or parafiine base oil, if during the manufacture of the lubricating oil, the wax is convertedinto the crystalline state by a distillation operation wherein the lubricating oil stock is thrown over as a distillate.

lVe have discovered a method whereby this may be satisfactorily and economically standard methods,

accomplished. At the same time we are able to produce such an improved lubricating oil in a very much larger quantity from the same stock than has heretofore been possible. Our invention embodies the preparation of a highly stabilized lubricating oil stock possessing to a great degree the desired green fluorescence and then blending or mixing this fluorescent stock with a lubricating oil stock which has been -prepared by standard methods. This latter stock to which the green fluorescent stock is added may be either the finished lubricating oil or it may be the stock from which the finished oil is to be prepared by standard methods. Likewise .th'e green fluorescent stock may be taken through a complete refining process for the production of a finished oil before it is added, in which case it is customarily added to a finished oil which has been prepared by or it may be added in an untreated or unrefined state to the stock from' which the lubricating oil which is prepared by standard methods is made, in which case the resulting mixture is treated by the normal or standard methods.

With the foregoing preliminary explana-' Distillation under vacuum serves to preserve the hydrogen content of the oil and has a marked, beneficial action on the remainder of the process. The fractions are then destructively distilled under pressure and high temperature and the residual oil used for the production of lubricating oil. Normally, the temperature in the destructive distilling operation is from 650 F. to 800 F., and the pressure from 50 to 150 pounds above atmospheric.

As an alternate method the petroleum oil may be subjected to requisite temperature and pressure to decompose or crack a part of such oil while producing a residuum con taining the desired stabilized lubricating oil gestion process, that is a process wherein the produced lower boiling point oils are held under sufficient pressure to substantially prevent their vaporization during the decomposing and stabilizing reactions. In which case the produced low boiling point oils may be separated from the petroleum oils not converted into low boiling point oils by a subsequent distillation or reducing operation.

When destructively distilling the oil the temperature and pressure and the time of heating will vary with the oil to be treated and the degree of decomposition desired. \Vith certain oils a temperature as low 050 F. and a pressure of 10 pounds above atmospheric will be sufficient. It will normally be found that the quality of finally produced lubricating oil can be controlled by controlling the degree of destructive distillation or heat treatment to which the oil is subjected under the proper conditions of temperature and pressure. The greater the degree of cracking the more stable will be resulting lubricating oil.

We have found that the resulting yield and quality of the lubricating oil obtained from the residual oil of a cracking process is influenced by the degree to which destructive distillation is carried. Also that for various stocks destructively treated, various degrees of cracking must be effected to produce the best results in the production of the lubricating stocks. As an illustration:

For a cracking stock composed of fractions which may be normally considered as lubricating fractio s, the yield and quality stocks having the green bloom, in a diof the finished lubricating oils from this process decreases after 20% of the original stock has been cracked and distilled over. On the other hand, when theheavy charging stock is mixed with say 40% of a lighter or solvent oil and destructively distilled, there is no decrease in yield or quality until after about 35% of the original charge has been cracked and distilled off. 1

During this destructive distillation it will be found that a large amount of the bodies that are unstable under the conditions of temperature and pressure employed have been cracked and distilled from the residual, or such unstable constituents have been polymerized and retained in the residual in a fornr more stable-at this temperature and pressure than the original oil. Thus far our process is the same as that set forth in the copending application referred to above. From this point on .we combine therewith the improvements embodied in our present invention. 4 The residuum obtained by the process as set forth above is preferably reduced until the resulting bottoms acquire a flash point approximating that of the stock which is to be used as a sourceof lubricating oil prepared by the normal or standard meth ods. These reduced bottoms are then added to a normal lubricating oil stock and the mixture reducedto the desired viscosityor fifiash, if necessary, treated with an acid,

filtered and otherwise refined as desired.

We prefer to add the reduced residual bottoms to a lubricating oil stock which has been obtained during the distillation operation in which thelubricating oil stock is thrown over and condensed as a distillate. Such lubricating oil distillates are encountered when it becomes necessary on an easternor parafiine base stock to distill the stock over for the conversion of its amorphous wax content into wax 'of the crystalline state. They are always encountered in separating the lubricating oil stocks from the tarry residue of asphaltic or mixed base crudes in the normal or standard methods ofpreparinglubricating oils from such asphaltic or mixed base crudesJ As avariation from this preferred manner of carrying out our invention, we may first take the residual bottoms from the destruc- .tive distillation part of our process and 5 treat them with an acid after which they may be reduced to the desired viscosity and -filtered or otherwise refined if desired, in order to make therefrom a finished high grade lubricating oil. ,This finished oil is 50 characterized by a rich green fluorescence.

It is then mixed in desired proportions witha finished lubricating oil which has been prepared by the normal or .standard methods, in which case there is imparted to the resulting oil a rich green fluorescence.

We may also if desired distill the residual bottoms resulting from the destructive distillation part of our process and resulting distillate as a source for hi h grade tics. For example, by de'structively distill-' ing a part of the stock from which our oil is made, to obtain the residuum which'we employ, a certain portion of our finished oil which has been highly stabilized by the intense heat to which it has been subjected. Due to this intense heat marked chemical changes or molecular rearrangements have taken place and certain unstable fractions, which would tend to break down if present in an oil used in internal combustion engines, are. either cracked and distilled off or later removed from the residuum, or they are poly: merized and retained in the oil in a muc there is produced from this source more stable form. Such oils, in addition to possessing the rich green fluorescence are red in color when viewed by transmitted light. They are characterized by higher Baum viscosity-gravity ratio, i. e., for the same viscosity they are always found to be heavier than the lubricating oils prepared by the normal or standard practice.

It is also true that the lubricating oil prepared from the residuum which we employ shows a marked reduction in the sulphur content. As a result, therefore, of blending this high grade stock with a lubricating stock which has been, oris to be, treated for a lubricating oil in the normal manner, we impart to the latter a proportionate amount of these improved characteristics so that our. final oil is of a character superior to oils made from the same crude by normal or standard methods. These advantageous results are obtained whether a finished oil, prepared from the above described residuum, is blended with a finished oil prepared by normal methods or whether the residuum is first mixed after beingreduced to a requiredfiash point, if

desired, with the stock from which the there results, during the subsequent treatment of the mixture for a final product, a more rapid separation of the acid sludge resulting from the acid treatment of the stock. Furthermore, following the neutralizing step, we have found that the separation oft-he neutralized substances is more complete, so that the usual brightening operation is very much reduced and in somecases obviated. Another and very important advantage of our invention is that petroleum oil can be treated, cracked or destructively distilled, and thereby a maximum production of gasoline obtained, simultaneously with the production of the residuum which we employ as a source of our highly stabilized and green bloom producing stock.

Our invention is capable of numerous modifications and is not therefore limited by the preceding description which has been given to illustrate our preferred process, but the invention is of the scope set forth in the following claims:

lVe claim:

1. The process of manufacturing a lubricating oilof green'fiuorescence from a petroleum oil normally yielding an oil of dif ferent fluorescence, which includes combining with such oil, oil from the residuum of a cracking process wherein a petroleum oil has been subjected to the requisite temperature and pressure to decompose part of the oil into relatively lower boiling point oil and to stabilize the residuum.

2. A method of producing lubricating oil from petroleum oil, which includes subjecting petroleum oil to the requisite temperature and pressure to decompose a part of such oil to form relatively lower boiling point oil while stabilizing the residuum, and

combining at least a part of such residuum with a petroleum Oll containing a lubrieating stock, and treating the resultant mixture to produce a finished lubricating oil.

3. The process of manufacturing lubrieating oils having a green fluorescence, which includes combining a part of the residuum obtained from a cracking operation wherein the requisite temperature and pressure has been employed to decompose part of the oil into relatively lower boiling point oil and to stabilize the residuum, with alubricating stock of different fluorcscenee.

4. In the art of manufacturing lubricating oil from petroleum oil, combining with lubricating oil stock, part of the residuum of a cracking operation wherein petroleum Oll is subjected to requisite temperature and pressure to decompose part of the oil into relatively lower boiling point oil and to stabilize part of the oil and to produce materials imparting a green fluorescence to the residuum.

5. In the art of producing a lubricating oil having a green fluorescence, that step in which oil from the residuum of a destructive distillation operation is combined with a lubricating oil stock prepared below the temperature and pressure at which any substantial part of the lubricating oil stock is decomposed.

6. A method of producing lubricating oil, which includes subjecting petroleum oil to the requisite temperature and pressure to decompose a part of such oil into relatively lower boiling point oil while substantially preventing vaporization of at least the relatively higher boiling point oil, so as to stabilize such undecomposed relatively high boiling point oil, combining part of the stabilized oil with a lubricating oil stock separated from crude at a temperature and pressure below such decomposing and stabilizing conditions.

7. A method of producing lubricating oil which includes subjecting petroleum oil to the requisite temperature and pressure to decompose a part of such oil into relatively lower boiling point oil while substantially preventing vaporization of at least the undecomposed relatively higher boiling point oil so as to stabilize such undecomposed relatively high boiling point oil, combining at least the lubricating oil stock from such stabilized oil with a petroleum lubricating oil stock separated from the crude bya normal process, that is one carried out at a temperature and pressure below such decomposing and stabilizing conditions, and refining together the combined stocks with sulphuric acid.

8. In the art of manufacturing lubrieating oil from petroleum oil the combined op-.

erations including subjecting petroleum oil to the requisite temperature and pressure to decompose a part of the oil into relatively lower boiling point oil while substantially preventing vaporization of the undecomposed relatively higher boiling point oil, so as to stabilize such undecomposed relatively high boiling point oil, reducing such stabilized oil to separate therefrom a lubricating oil stock, mixing such stock with lubricating fractions obtained from petroleum oil by reducing or distillation operation carried out below such decomposing and stabilizing conditions of temperature and pressure, and treating the resultant mixtureto finish the lubricating oil.

'9. In the art of manufacturing lubricating oil from petroleum oil, the combinedoperations including subjecting petroleum oil to a stabilizing action carried out under a temperature not less than 650 F. and a pressure not less than 10 pounds per square inch, reducing the residuum to separate lubricating stock from the other constitu ents thereof, mixing such stock with lubrioil below such stabilizing conditions, and cons oil stock, and lubricating oil obtained 1 refining, the resultant m xture -with sul from petroleum by operations carried out phuric aeidg below such stabilizing conditions of temlOQA "lubricating .oil possessing a. green perature and pressure. V 4 i 5 fluorescence comprising a" Combination of Si ed at Richmond, Calif, this 17th'da'y i I lubricating oil from the residjle of a. crackof April, 1924. ing processwherein the requisite tempera-i' RICHARD. w. HANNA.

1 ture and pressure have been maintainedio ELPSWORTH Q S A produce a polymerized and stabilized vis THEODORE WILLIAM DOELL; 

